A strong earthquake shook Southern California on Tuesday, causing buildings to sway and triggering some precautionary evacuations. No immediate damage was reported.

The jolt was felt from Los Angeles to San Diego, and slightly in Las Vegas.

Preliminary information from the U.S. Geological Survey estimated the quake at magnitude 5.4, centered 29 miles east-southeast of downtown Los Angeles near Chino Hills in San Bernardino County. Ten aftershocks occurred in the next dozen minutes, including three estimated at 3.8.

Los Angeles Fire Department spokesman Brian Humphrey said there were no immediate reports of damage or injury in Los Angeles. San Bernardino County fire dispatch also had no immediate reports of damage.

The quake struck at 11:42 a.m. PDT. Buildings swayed in downtown Los Angeles for several seconds.

Workers quickly evacuated some office buildings.

"It was dramatic. The whole building moved and it lasted for a while," said Los Angeles County sheriff's spokesman Steve Whitmore, who was in the sheriff's suburban Monterey Park headquarters east of Los Angeles.

In Orange County, about 2000 detectives were attending gang conference at a Marriott hotel in Anaheim when a violent jolt shook the main conference room.

Mike Willever, who was at the hotel, said, "First we heard the ceiling shaking, then the chandelier started to shake, then there was a sudden movement of the floor."

Chris Watkins, from San Diego, said he previously felt several earthquakes, but "that was one of the worst ones."

Delegates and guests at a cluster of hotels near the Disneyland resort spilled into the streets immediately after the quake.